The present invention relates to a device for joining pre-cast (prefabricated) concrete sections, the device comprising a cable loop, wherein the cable sections forming the loop have means for keeping the cable sections in a bent-over position. The invention also relates to a pre-cast concrete section having a device of the kind described above.
A non-elastically deformable belt having an internally disposed core of stiff, deformable material, which is surrounded by a plurality of twisted strands, which in turn are surrounded by a casing, is known from French patent application publication FR-A-1602226.
Devices of the kind having a cable loop for joining pre-cast concrete sections, particularly prefabricated wall elements of concrete, are well-known from the prior art. Devices of this kind usually comprise a retaining part in the form of a rail, which is of U-shaped construction and which at the end is led into the pre-cast concrete section. It is necessary for transport and also during mounting of such a pre-cast concrete section that the cable loop substantially does not protrude beyond the edge face. To that extent it has to be achieved that the cable loop is received by the retaining part, i.e. substantially does not protrude beyond the retaining part.
In this connection, various devices are known from the prior art, which in principle do justice to this premise. Thus, for example, a receiving box is known from European patent application publication EP 1 637 670 A1, which has a removable cover, wherein the cable loop, which projects through an opening on the rear side of the receiving box, is held under stress against the removable cover by a spreading spring during transport and also during mounting. When the cover is removed, the cable loop shoots forward, not only due to the bias through the spreading spring but also due to the resilient characteristics of the cable loop, and goes over, for example in the case of an upright wall section, into an approximately horizontal position. That means the cable loop extends in the direction of the edge face of the opposite pre-cast concrete section.
The outlay which is necessitated in accordance with the prior art, in order to keep the cable loop during transport and mounting in a state bent over by approximately 90° and thus parallel to the upper side of the pre-cast concrete section, is high, and for that reason such devices are also very expensive.
Moreover, a device is known from European Patent EP 0 914 531 B1, which similarly comprises a U-shaped retaining part, which has on the rear side a passage opening for the cable loop, wherein the retaining part is of approximately U-shaped construction and wherein the limbs are bent over inwardly at the end. The cable loop now projects by its loop-shaped end through the opening, which is arranged on the rear side, in the retaining part and bears from within against the bent-over portions of the limbs of the retaining part. After mounting, the cable loop is pulled out of the retaining part by the loop-shaped end, whereby the cable loop snaps up.
German utility model DE 20 2007 011 243 U1 shows a similar construction insofar as a shaped part is provided there for fixing the cable loop, which shaped part has a mechanically positive couple with the section, which forms the bent-over cable eye, of the cable on at least three sides and which shaped part, after casting of the concrete pre-cast concrete section, may be withdrawn from the concrete pre-cast section and the cable eye.
In this connection, the outlay for keeping the cable loop in the bent-over state is relatively high, particularly because a specially constructed rail has to be produced as a retaining part, and in addition, the cable loop in the transfer to the pre-cast concrete section is kept by an insert body in the opening of the retaining part. This device is thus also comparatively expensive.
Finally, a device is known from European Patent EP 0 534 475 B1, in which an insert dish part is provided as well as a cover, wherein the insert dish part receives the cover by means of a snap connection. The loop-shaped end is kept parallel to the edge face of the pre-cast concrete section by the insert dish part in conjunction with the cover. It is also the case here that production of such a device is complicated and costly.
A cable transport anchor having a loop at the end is known from German published patent application DE 33 22 646 A1. The guiding together and bending over of central cable regions are carried out by a guiding and bending-over device which is formed by a sleeve.